Tubular writing head for a tubular writing pen

ABSTRACT

The present invention is directed to a tubular writing head of a tubular writing pen, wherein the tubular writing head comprises a hollow cylindrical member having a writing tube mounted at one end thereof and the interior thereof containing a drop weight with a hair wire which extends through the tube. A loading member in the form of a mushroom-shaped member is also disposed within the interior of the hollow cylindrical member and acts upon the drop weight so as to cause the hair wire to extend through the tube even when the tubular writing pen is not held in a vertical position.

United States Patent TUBULAR WRITING HEAD FOR A TUBULAR WRITING PEN 3Claims, 1 Drawing Fig.

U.S. Cl 401/258 Int. Cl 843k 1/10 Field of Search 401/259 [5 6]References Cited UNITED STATES PATENTS 3,455,639 7/1969 Danjczek 401/2593,466,132 9/1969 Riepe 401/259 Primary Examiner-Lawrence CharlesAttorney-Burton L. Lilling ABSTRACT: The present invention is directedto a tubular writing head of a tubular writing pen, wherein the tubularwriting head comprises a hollow cylindrical member having a writing tubemounted at one end thereof and the interior thereof containing a dropweight with a hair wire which extends through the tube. A loading memberin the form of a mushroom-shaped member is also disposed within theinterior of the hollow cylindrical member and acts upon the drop weightso as to cause the hair wire to extend through the tube even when thetubular writing pen is not held in a vertical position.

TUBULAR WRITING HEAD FOR A TUBULAR WRITING PEN BACKGROUND OF THEINVENTION The present invention relates to a writing head for tubularwriting pens and comprises a cylindrical member formed with a screwthread, a preferably helical venting channel and a bore containing adrop weight, a writing tube adjoining said bore, a hair wire extendingfrom the underside of said drop weight and a retaining means in theupper part of said cylindrical member for preventing said drop weightfrom falling out. The purpose of the drop weight and of the hair wireattached thereto is to regulate the flow of the ink whereby the clearingaction of the moving hair wire prevents the bore in the writing tubefrom becoming blocked. When the end of the tubularwriting pen is appliedto a surface the hair wire is automatically pushed back into the writingtube and permits ink to issue from the tube. In other words, ink willusually begin to flow from the writing tube as soon as thetubular-writing pen is applied to a surface. Thus, a tracing or writingcan be produced on the surface at once.

However, since the drop weight is controlled entirely by gravity, it ispossible that the hair wire will not project from the writing tube in arest position when the tubular-writing pen is held at an angle withrespect to vertical, or even horizontally, as may well be the case whendrawing on an inclined or vertically placed drawing board. The ink inthe tube will then form an inverted meniscus and, when thetubular-writing pen is applied to the writing surface, the ink will notmake contact therewith and consequently no ink will be drawn from thepen. When this occurs the drop weight must first be moved into itsproper position by shaking the pen. This is a nuisance and mostinconvenient.

SUMMARY It is therefore an object of the present invention to provide atubular-writing head of a writing pen constructed in a manner whereinthe hair wire will always project from the tube thereof even when thepen is held at an angle with respect to vertical or horizontally.

In accordance with the principles ofthe present invention there isprovided a tubular-writing head comprising a cylindrical member havingan externally formed screw thread and venting channel and an internallyformed bore, a drop weight is mounted within thebore. A writing tubeadjoins the bore and a hair wire extends from the end of the drop weightnearer to the writing tube and passes through the latter. Retainingmeans in the part of the cylindrical member remote from the writing tubeare provided for preventing the drop weight from falling out, and aloading member is mounted inside the bore for engagement with the otherend of the drop weight and for applying thrust to the drop weight in thedirection towards the writing tube even when the pen is held at an angleother than vertical.

The loading member preferably has the shape of a pestle or mushroom, thehead of which bears against the top of the drop weight, and the centerof gravity of which is located in the upper end of its stem. When thetubular writing pen is tilted, the loading member tips over in a mannersuch that only the edge of its head touches the drop weight. The loadingmember is thus capable of applying a thrust to the drop weight urging ittowards the writing tube even when the pen is held at an angle withrespect to vertical or horizontally, and of thus forcing the end of thehair wire out of the writing tube into a position in which the pen isimmediately ready for. writing.

In order to provide for the tilting of the loading member the stem ofthe pestle or mushroom extends through an opening in the bottom of a cupinserted into the bore. This cup prevents the drop weight and theloading member from falling out.

The loading member may be made to occupy a defined position by limitingits angle of tilt by the arrangement between the edge of its head andthe bottom of the cup.

In order to permit the head of the tubular-writing pen to be cleaned andalso in order to permit a defective or unsuitable loading member to beremoved, the cup which prevents the loading member from falling out maybe made replaceable.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, features andadvantages of the present invention will become more apparent byreference to the accompanying drawing, wherein FIG. 1 is an axialsectional view of the writing head of a tubular-writing pen constructedin accordance with preferred embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing,there is shown a tubular-writing head comprising a hollow cylindricalbody 2 which is screwed into a mount 1. A chamber 9 serves as acommunication path between the writing head of the tubular-writing penand the barrel of the pen (not shown) which contains an ink reservoir.The bore 6 of the cylindrical body 2 contains a drop weight 3 disposedtherewithin. A hair wire 7 is attached to the bottom side of the dropweight nearer to a writing tube 8 and extends through the writing tube8, projecting from the outer end thereof in its normal or rest position.A mushroom-shaped loading member 4 is also located inside the boreand-disposed above the drop weight; the stem of the loading memberextending through an opening 11 in a cup-shaped member 5 which serves toprevent the drop weight from falling out of the bore. When the pen isheld vertically, the face of the mushroom head rests on the end face ofthe drop weight remote from the writing tube. However, when the pen istilted, the loading member will also tilt into a position, such as thatillustrated. This is due to the fact that the center of gravity of theloading member is located near the upper end of its stem. As will beunderstood from the drawing, the angle of tilt is determined by theposition of the bottom of the cup. Only the edge of the mushroom headwill then bear on the end face of the drop weight, and a pointdiametrically opposite the point of contact is retained by the bottom ofthe cup. The freely projecting stem of the loading member will provideleverage which will urge the drop weight away from the cup in adirection towards the writing tube. Hence, the hairwire will be urged toproject from the writing tube even when the pen is held at an angle withrespect to vertical or horizontally, whereby the pen will be readilyaccessible for writing in every position in' which it may, in actuality,be held.

In order to permit the writing head of the pen and the loading member tobe replaced or cleaned, the cup 5 can be lifted out of the bore. Toaccomplish this, the cylindrical member 2 is unscrewed from the mount 1and the cup, which has a flange or lip 5a resting on the-top of thecylindrical member 2, can be removed therefrom. Thus, the loadingmember, as well as the drop weight, are easily removable from the bore6.

A bore 10 connects the chamber 9 with a helical venting channel 12, inorder to equalize the air pressure in the ink reservoir with that of theambient pressure.

In an alternative embodiment of the invention, the ink reservoir may beconnected to the venting channel via two slots formed in the wall of thecylindrical member on opposite sides thereof. However, in thisembodiment, the flange or lip 5a of the cup 5 would be formed with adiscontinuous surface so as to prevent said flange from covering theslots. The flange 5a would then preferably consist of a plurality oflugs. If the number of lugs were odd, the cup could be inserted inanyposition since at least. one of the slots would always remain uncoveredto provide communication between the ink reservoir and the ventingchannel.

While I have shown and described the preferred embodiment of myinvention, it will be readily apparent to those skilled in the art thatthere are many modifications, changes and improvements which may be madetherein without departing from the spirit and scope thereof as definedbythe appended claims.

I claim: l. A tubularwriting head for a tubular-writing pen, saidwriting head comprising; a cylindrical member having an externallyformed screw thread, an externally formed venting channel, and aninternally formed bore, a drop weight positioned within said bore, awriting tube connected to said cylindrical member adjoining said bore, ahair wire extending from the one end of the drop weight disposed nearerto said writing tube and therethrough, retaining means in the form of acupshaped member disposed within the bore of said cylinder remote fromsaid writing tube for preventing said drop weight from falling out ofsaid cylinder, means disposed in said bore for urging said drop weightin a direction towards said writing tube, said means being asubstantially free-floating tiltable mushroom-shaped loading memberhaving a head portion and a stem portion connected thereto, the face ofsaid, head portion, being of a slightly smaller diameter than thediameter of said bore, and being disposed within said bore occupying adefined position limited by the angle of tilt of said loading member,and the center of gravity of said loading member residing in the upperend of said stem portion, said cup-shaped member having an opening inthe bottom thereof and said stem portion of said loading memberextending through said opening, the thrust and pressure applied to saiddrop weight by said loading member is in a direction towards the writingtube, and is essentially restrained when said pen is in a position otherthan vertical, whereby ink flow is smoothly regulated and the clearingaction of said hair wire in said writing tube is facilitated so as tominimize forming an inverted meniscus in said writing tube, and saidcup-shaped member prevents said drop weight and said loading member fromfalling outwardly from said bore.

2. A tubular writing head as claimed in claim 1, wherein said cup-shapedmember is removably disposed within said bore.

3. A tubular writing head as claimed in claim 1, wherein the angle oftilt of said loading member is defined by the distance between thebottom of said cupshaped member and said other end of said drop weight.

1. A tubular-writing head for a tubular-writing pen, said writing headcomprising; a cylindrical member having an externally formed screwthread, an externally formed venting channel, and an internally formedbore, a drop weight positioned within said bore, a writing tubeconnected to said cylindrical member adjoining said bore, a hair wireextending from the one end of the drop weight disposed nearer to saidwriting tube and therethrough, retaining means in the form of acup-shaped member disposed within the bore of said cylinder remote fromsaid writing tube for preventing said drop weight from falling out ofsaid cylinder, means disposed in said bore for urging said drop weightin a direction towards said writing tube, said means being asubstantially free-floating tiltable mushroom-shaped loading memberhaving a head portion and a stem portion connected thereto, the face ofsaid head portion, being of a slightly smaller diameter than thediameter of said bore, and being disposed within said bore occupying adefined position limited by the angle of tilt of said loading member,and the center of gravity of said loading member residing in the upperend of said stem portion, said cup-shaped member having an opening inthe bottom thereof and said stem portion of said loading memberextending through said opening, the thrust and pressure applied to saiddrop weight by said loading member is in a direction towards the writingtube, and is essentially restrained when said pen is in a position otherthan vertical, whereby ink flow is smoothly regulated and the clearingaction of said hair wire in said writing tube is facilitated so as tominimize forming an inverted meniscus in said writing tube, and saidcup-shaped member prevents said drop weight and said loading member fromfalling outwardly from said bore.
 2. A tubular writing head as claimedin claim 1, wherein said cup-shaped member is removably disposed withinsaid bore.
 3. A tubular writing head as claimed in claim 1, wherein theangle of tilt of said loading member is defined by the distance betweenthe bottom of said cup-shaped member and said other end of said dropweight.